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Sida is a genus of flowering herbs in the family Malvaceae, which includes several species that are weeds in Brazil. Plants of a Sida sp. exhibiting symptoms characterized by stunting, chlorosis, small leaves, and witches'-broom, indicative of infection by phytoplasmas, were found in a field previously cultivated with tomato, located in the region of Campinas, State of São Paulo, in December 2008. To demonstrate the presence of phytoplasmas in diseased tissues, DNA was extracted from shoots and leaves from three symptomatic and eight asymptomatic plants. Nested PCR was performed using primers P1/Tint followed by primer pair R16F2n/R16R2 (1). DNA fragments of 1.2 kb, corresponding to 16S rDNA, were amplified only for DNA from two symptomatic samples. Phytoplasma identification was initially carried out by restriction fragment length polymorphism (RFLP) analysis through digesting the PCR products with the restriction enzymes AluI, HhaI, HaeIII, HpaII, MseI, and RsaI. The two phytoplasma isolates found to be infecting a Sida sp. showed identical RFLP patterns, which were indistinguishable from the phytoplasma previously reported in association with hibiscus (Hibiscus rosa-sinensis) witches'-broom in Brazil (2). Nucleotide sequence alignment revealed that 16S rDNA of both phytoplasma isolates found in a Sida sp. (GenBank Accession No. HQ230579) shared 99.9% sequence similarity with 16S rDNA from hibiscus witches'-broom phytoplasma (HibWB) (GenBank Accession No. AF147708). HibWB is the representative of the 16SrXV group and it was proposed as a putative species nominated “Candidatus Phytoplasma brasiliense” (2). The disease is frequently observed in hibiscus plants used as ornamentals in the states of São Paulo (4) and Rio de Janeiro (2). “Ca. Phytoplasma brasiliense” has only been reported in Brazil to be infecting hibiscus (2,4) and periwinkle (Catharanthus roseus) (3). The presence of a phytoplasma belonging to group 16SrXV in a Sida sp. expands its natural host range. The role of this weed as a potential source of inoculum for crops should be investigated. References: (1) I. M. Lee et al. Int. J. Syst. Bacteriol. 48:1153, 1998. (2) H. G. Montano et al. Int. J. Syst. Evol. Microbiol. 51:1109, 2001. (3) H. G. Montano et al. Plant Dis. 85:1209, 2001. (4) E. G. Silva et al. Summa Phytopathol. 35:234, 2009.

A thermotolerant, Gram-stain-positive, aerobic, sporangium-forming actinomycete, strain RA45T, was isolated from a desert region in Xinjiang Uigur Autonomous Region, north-western China. Comparative analysis of the 16S rRNA gene sequence and phenotypic characterization revealed that strain RA45T belonged phylogenetically to the family Pseudonocardiaceae of the suborder Pseudonocardineae. Strain RA45T showed more than 5 % 16S rRNA gene sequence divergence from recognized species of genera in the family Pseudonocardiaceae, forming a distinct lineage within the evolutionary radiation occupied by the genera Amycolatopsis, Prauserella, Thermocrispum, Saccharomonospora, Saccharopolyspora and Sciscionella, but distinct from each of them. The affiliation to the family was supported by the presence of suborder- and family-specific 16S rRNA signature nucleotides, a DNA G+C content of 69.9 mol%, the presence of meso-diaminopimelic acid, ribose, arabinose, glucose and galactose, which are characteristic components of cell-wall chemotype IV of actinomycetes, the presence of menaquinone MK-9(H4) as the major respiratory lipoquinone, a lack of mycolic acids and the presence of an N-acetylated type of muramic acid. However, strain RA45T differed from known genera of the family in its polar lipid composition: the major phospholipids were phosphatidylethanolamine, phosphatidylinositol mannosides, phosphatidylmethylethanolamine, diphosphatidylglycerol, phospholipids of unknown structure and phospholipids of unknown structure containing glucosamine (phospholipid type IV). Based on its morphological, chemotaxonomic and phylogenetic characteristics, strain RA45T is considered to represent a novel species of a new genus in the family Pseudonocardiaceae, for which the name Yuhushiella deserti gen. nov., sp. nov. is proposed. The type strain of Yuhushiella deserti is RA45T (=CGMCC 4.5579T =JCM 16584T).